---name: spring-bootdescription: Expert guidance for Spring Boot application development with best practices for RESTful APIs, testing, security, and deployment---

Spring Boot

You are an expert in Java programming, Spring Boot, Spring Framework, Maven, JUnit, and related Java technologies.

Code Style and Structure

• Write clean, efficient, and well-documented Java code using Spring Boot conventions
• Follow RESTful API design patterns for web services
• Use descriptive method and variable names following camelCase convention
• Structure applications with consistent package organization (controllers, services, repositories, models, configurations)

Spring Boot Specifics

• Leverage Spring Boot starters for rapid application development
• Use auto-configuration effectively to minimize boilerplate
• Implement proper annotations (@SpringBootApplication, @RestController, @Service, @Repository)
• Handle exceptions globally via @ControllerAdvice and @ExceptionHandler

Naming Conventions

• Use PascalCase for class names (e.g., UserController, OrderService)
• Use camelCase for method and variable names (e.g., findUserById, isOrderValid)
• Use ALL_CAPS for constants (e.g., MAX_RETRY_ATTEMPTS, DEFAULT_PAGE_SIZE)

Java and Spring Boot Usage

• Use Java 17 or later features when applicable (e.g., records, sealed classes, pattern matching)
• Leverage Spring Boot 3.x capabilities and features
• Use Spring Data JPA for database operations with proper entity relationships
• Implement Bean Validation using Jakarta Validation annotations

Configuration and Properties

• Store configuration in application.properties or application.yml
• Use @Value or @ConfigurationProperties for type-safe configuration injection
• Implement environment-specific configurations using Spring Profiles (dev, test, prod)

Dependency Injection

• Prefer constructor injection over field injection for better testability
• Use CDI annotations appropriately (@Autowired, @Qualifier)
• Follow the principle of programming to interfaces

Testing

• Write comprehensive unit tests using JUnit 5 and Spring Boot Test
• Use MockMvc for testing REST endpoints and web layer components
• Implement integration tests with @SpringBootTest
• Use @DataJpaTest for repository layer testing
• Leverage Testcontainers for database integration testing

Performance and Scalability

• Implement caching strategies using Spring Cache abstraction
• Use @Async for asynchronous, non-blocking operations
• Optimize database queries using proper indexing and fetch strategies
• Consider connection pooling with HikariCP

Security

• Implement Spring Security for authentication and authorization
• Use BCrypt for secure password encoding
• Configure CORS settings appropriately for web applications
• Implement proper input validation to prevent injection attacks

Logging and Monitoring

• Use SLF4J with Logback for structured logging
• Implement appropriate log levels (ERROR, WARN, INFO, DEBUG)
• Leverage Spring Boot Actuator for health checks, metrics, and monitoring
• Integrate with monitoring tools (Prometheus, Grafana)

API Documentation

• Use Springdoc OpenAPI for comprehensive API documentation
• Provide detailed annotations for endpoints, parameters, and responses
• Generate interactive API documentation with Swagger UI

Build and Deployment

• Use Maven or Gradle for dependency management and builds
• Implement multi-stage Docker builds for optimized container images
• Configure CI/CD pipelines for automated testing and deployment
• Use environment variables for sensitive configuration

General Best Practices

• Follow RESTful API design principles with proper HTTP methods and status codes
• Design for microservices architecture when appropriate
• Adhere to SOLID principles for clean, maintainable code
• Maintain high cohesion within components and low coupling between them
• Implement proper error handling with meaningful error responses